Support insulator



May 4, 1954 s. R. SMITH, JR

SUPPORT INSULATOR Filed Nov. 20', 1951 as ,L) 33 19 as Z 34 i g I7 Z5 Z4 Inventor":

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Patented May 4, 1954 SUPPORT INSULAT'OR Sidney R. Smith, Jr., Pittsfield, Mass, assignor to General Electric Company, a corporation of New York Application November 20, 1951, Serial No. 257,317

11 Claims. 1

This invention relates to supports of electrical insulating materials and more particularly to a column-type support or insulator employed to support and space terminals and contacts of open type fused cutouts, switch blades, and the like.

The conventional column-type support insulator usually consists of a solid or hollow body portion of porcelain with a series of integral flanges or petticoats extending circumferentially around the body to increase the electrical creep or strike distance between terminal and contact hardware mounted at opposite ends of the insulator, and between this hardware and the insulator support hanger mounted intermediate the ends of the insulator. The terminal hardware extending transverse to the axis of the insulator in one direction has either been clamped to the opposite ends thereof by a metallic clamp extending circumferentially around the insulator or has been cemented in radially extending openings in the insulator, while the metallic support hanger extending transverse to the axis of the insulator in the opposite direction has usually been clamped to the insulator intermediate the ends thereof by a girth clamp around this portion of the insulator. In order to further increase the creep or strike distance between hardware of diiierent potential and to prevent false operation of the device caused by birds and other animals bridging the hardware, an arrangement has recently been devised in connection with which the insulator support hanger as well as the terminal hardware was also cemented in a radial opening in the insulator. Although this arrangement has been satisfactory for some applications, there are other applications where it is desired, especially from a mechanical strength point of View, to retain the mechanical bolting method of affixing hardware to the insulator, although not at the expense of reducing the strike distance, as is the case when prior art mechanical girth clamps and bolts are employed. More- .over, insofar as the insulator proper is concerned, there are other undesirable features associated with most prior art insulators which it is desired to correct. For the higher rated devices, for example, a porcelain insulator, especially when of the solid type, has a diameter which is very difficult to vitrify thoroughly to the center. The porcelain sections are very thick, and are consequently subject to internal drying and firing strains, and the porcelain is not as resistant to thermal shock as would be a similar ceramic piece with thinner sections.

It is therefore an object of this invention to provide a column-type insulator to which hardware may be bolted, but which nevertheless presents an electrical creep or strike distance equal or greater than that provided by prior art support insulators having hardware cemented in openings therein.

It is also an object of this invention to provide a column-type porcelain insulator comprised of relatively thin sections whereby all portions thereof may be uniformly vitrified during manuiacture.

The invention will be better understood from the following description when taken in connection with the accompanying drawing and the scope of the invention will be pointed out in the appended claims. In the drawing, Fig. 1 is a side elevation of a fused disconnecting switch or cutout embodying the support insulator of the invention and showing the switch in the circuit closed position and Fig. 2 is a section taken on the line 2-2 of Fig. 1.

For the purpose of illustrating my invention, I have shown in Fig. l a fused disconnecting switch of the open dropout type wherein a line terminal it and a relatively stationary contact electrically connected to the terminal, are supported adjacent one end of an insulator support 82, while a hinge means or hook type bearing member 13 is supported on support 12 adjacent the opposite end thereof. Another terminal i l and a second relatively stationary contact, not visible and electrically connected to terminal I l, are suitably mounted on bearing memher it. To serve as a support for an expulsion tube iii, a hinge element it of conducting material is provided, having trunnion ll adapted to be inserted in the hooks is of the bearing element :3. Hinge element or support it is also provided with a contact, not visible, movable into and out of engagement with the relatively stationary contact connected to terminal l4, upon rotation of the hinge element.

For completing a conducting path between the terminals Hi and M, a current conducting means is provided and comprises a conductor [9 including a portion within the tube [5 which is fusible at a predetermined value of current. Conductor it? including the fusible portion is mounted within the expulsion tube [5 with one end of the conductor suitably connected electrically to conducting cap 20, threadedly mounted on the upper end of tube 15 and engageable with stationary contact means 1!. As shown, the tube 15 is directly secured by clamp 2|, which in turn is pivotally mounted at 22 on hinge support element l6, constituting-therewith a toggle which is held in the rigid condition shown by clamping the end of conductor it between the hinge element and a nut 23, which may be drawn tight by a screw 24. For maintaining the switch or contact bridging member in the closed circuit position shown in the drawing, there is provided a holding means which may be of any conventional type, such as the one illustrated, which comprises a U-shaped resilient member 25, the outer ends of the legs of which are bent inwardly and then outwardly to provide, in V-shape formation, flared ends which yield sufficiently to permit entrance of contact cap 20, and thereupon close over the cap to prevent reverse movement. U-shaped holding member 25, terminal i0, leaf contact spring II and, in addition, a leaf backing spring H, are all carried by a bracket 26 extending outwardly from insulator l2 and directly supported thereon by a means to be discussed hereinafter. Bearing member [3 and a hanger arm 21, employed for mounting the insulator on a cross-arm or pole, are also directly mounted thereon or connected thereto in a similar manner by this means. Aside from the insulator l2 and the means for directly mounting the switch elements thereon, the fuse disconnecting switch as thus far described is identical to the one disclosed in United States Letters Patent No. 2,574,401 (Serial No. 68,016) Lesher, granted November 6, 1951, and assigned to the same assignee as the present application.

However, in accordance with my invention, the elongated column-type support insulator l2 provided is distinguishing or novel and comprises a relatively small and solid axially extending core portion 28 extending substantially the full length of the insulator having a plurality of relatively large axially extending webs 29 integral with and projecting radially therefrom. A plurality of relatively large axially spaced webs 30, which may better be described as ribs insofar as the Fig. 1 view is concerned, extend transverse to the longitudinal axis of the insulator and interconnect adjacent surfaces 34 of the axially extending webs 25. Although Fig. 2 illustrates a crosssection taken midway the ends of the insulator, it is a typical illustration of the cross-sections intermediate any of the transversely extending webs, and shows that these portions of the insulator have a solid cruciform configuration, while the transversely extending webs have a solid circular configuration. Although the web portions intermediate the transverse ribs may be vertically offset with respect to each other without departing from the scope of my invention, it will be observed that, insofar as the particular insulator illustrated is concerned, the web portions between a pair of adjacent rib portions are angularly so positioned with respect to each other that each web is vertically aligned with a correspondingly positioned web between each adjacent pair of ribs.

For the purpose of connecting the metallic hanger arm 21 to the insulator, one of the axially extending webs is provided with an aperture 32 transversely therethrough intermediate the ends of the insulator, while a pair of axially extending and vertically aligned webs respectively adjacent the ends of the insulator and positioned dimetrically opposite to the hanger arm support web are provided with similar apertures to facilitate mounting of the terminals, contacts, and contact bridging means previously discussed. As pointed out, these elements are either mounted on bracket 26 or hook-type bearing member [3, which are in turn each integrally connected or rigidly fixed respectively to a channel or U-shaped member 33 having aligned apertures through the legs thereof, while hanger arm 2'! is also rigidly fixed to a similar U-shaped member. As better illustrated in Fig. 2, each U-shaped member is positioned about an axially extending web adjacent one of the apertures 32, with a resilient gasket or 34 such as rubber interposed therebetween and bolted to the web by means of a bolt 35 extending through the apertures in the web and the apertures in the U-shaped member, and by means of a nut 36 drawn up on threads of the bolt, whereby the assembly is rigidly clamped to the web. Because of tolerance limitations, and to allow for the use of various size bolts, the apertures in the axially extending webs may be made excessively large and a bushing 31 of insulating material provided as illustrated. Although not absolutely essential, it will be observed that the front or vertical edge of the apertured web at the lower end of the insulator has been provided with flared portions 38, while the upper horizontal edge of the apertured web at the upper end of the insulator has also been provided with similar flared portions 39. This sort of design furnishes a compartment within which the legs of the U-shaped member or clamp nests and prevents rotation of the clamp about the apertures as a center. Thus, I have provided a support insulator to which hardware may conveniently be bolted, and at the same time provided one having an exceptionally long electrical creep or strike distance between hardware of different potentials.

While 1 have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangement shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A non-metallic elongated column-type insulator comprising a relatively small and solid axially extending core portion, a plurality of axially extending webs integral with and projecting radially from said core portion, a plurality of axially spaced webs extending transverse to the longitudinal axis of said insulator and interconnecting adjacent surfaces of said axially extending webs, said axially extending and axially spaced webs being relatively large with respect to said relatively small core portion.

2. An elongated insulator constructed entirely out of an insulating material with a solid core portion comprising a plurality of spaced rib portions, each having a solid circular cross-section transverse to the longitudinal axis of said insulator, and a plurality of relatively large radially extending webs interconnecting adjacent rib portions.

3. An non-metallic elongated insulator having a solid and relatively small core portion extending substantially the length thereof comprising a plurality of spaced rib portions, each having a solid circular cross-section transverse to the longitudinal axis of said insulator, and a plurality of relatively large webs disposed transverse to said rib portions extending radially from said axis and interconnecting adjacent rib portions.

4. A non-metallic column-type insulator having a relatively small and solid core portion ex tending substantially the full length thereof comprising a plurality of spaced rib portions each having a solid circular cross-section, and web portions interconnecting adjacent rib portions, the cross-section of said web portions having a solid cruciform configuration, said rib and web portions being relatively large with respect to said relatively small core portion.

5. A column-type insulator composed entirely of an insulating material having a relatively small solid core portion extending substantially the full length thereof comprising a plurality of relatively large spaced rib portions each having a solid circular cross-section, relatively large web portions interconnecting adjacent rib portions, and web portions defining opposite ends of said insulator, the cross-section of said web portions intermediate adjacent rib portions and said end defining web portions having a solid cruciform configuration.

6. A column-type insulator comprising a plurality of spaced rib portions each having a solid circular cross-section normal to the longitudinal axis of said insulator and web portions extending parallel to said axis interconnecting adjacent rib portions, the cross-section of said web portions intermediate adjacent rib portions having a solid cruciform configuration normal to said axis, said insulator constructed entirely out of a dielectric material with a relatively small solid core portion extending substantially the full length thereof, said rib and web portions being relatively large with respect to said relatively small core portion.

7. An elongated insulator comprising a plurality of circular-shaped rib portions, each having a solid circular cross-section transverse to the longitudinal axis of said insulator and web portions interconnecting adjacent rib portions, each of said web portions between a pair of adjacent rib portions comprising a plurality of webs extending radially from said axis and angularly positioned with respect to each other so that each web will be aligned with a correspondingly positioned web between each adjacent pair of ribs, said insulator having a relatively small solid core portion and said rib and web portions being relatively large with respect to said relatively small solid core portion, a section through said web portions taken normal to said axis between a pair of adjacent rib portions presenting a solid surface of insulating material which is substan" tially cruciform in configuration.

8. In combination, a column-type insulator comprising a plurality of circular-shaped rib portions spaced and interconnected by web portions, a web adjacent one end of said insulator having an aperture extending transversely therethrough, a second web having an aperture therethrough adjacent the opposite end of said insulator and in alignment with said first-mentioned web, a third web having an aperture transversely therethrough intermediate the ends of said insulator and positioned diametrically opposite said first and second mentioned webs, a pair of spaced electrical conductor terminals, an insulator hanger arm and means for mounting said conductor terminals respectively on said aligned webs and said hanger arm on said diametrically positioned web including bolts having threaded ends respectively extending through said apertures and nuts respectively engaging the threads on said bolts.

9. An elongated column-type insulator comprising an axially extending solid core portion, a plurality of axially-extending webs integral with and projecting radially from said core portion, a

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plurality of axially spaced webs extending transverse to the longitudinal axis of said insulator and interconnecting adjacent surfaces of said axially extending webs, one of said axially extending webs having a pair of apertures extending transversely therethrough and respectively positioned adjacent opposite ends of said insulator, another of said axially extending webs projecting radially from said core portion in a direction opposite to the direction of projection of said one web and having an aperture extending transversely therethrough positioned intermediate the ends of said insulator, a pair of spaced electrical conductor terminals, an insulator hanger arm and means for mounting said conductor terminals on said one Web respectively adjacent opposite ends of said insulator and said hanger arm on said another web intermediate the ends of said insulator including bolts having threaded ends respectively extending through said apertures and nuts respectively engaging the threads on said bolts.

10. An elongated column-type insulator for the support of hardware having different electrical potential comprising an axially extending core portion, a plurality of axially extending webs integral with and projecting radially from said core portion, a plurality of axially spaced circular-shaped rib portions integral with said core portion and integrally inter-connecting adjacent webs, one of said webs positioned on one side of the longitudinal axis of said insulator having an aperture extending transversely therethrough to accommodate a bolt for mounting hardware of a given potential and another of said webs positioned on an opposite side of said longitudinal axis having an aperture extending transversely therethrough to accommodate a bolt for mounting hardware of a potential different than the potential of the hardware to be mounted on said one web, said apertures longitudinally spaced from each other and at least one of said rib portions positioned therebetween.

11. An elongated column-type insulator for the support of hardware having different electrical potential comprising an axially extending core portion, a plurality of axially extending webs integral with and projecting radially from said core portion, a plurality of axially spaced circular-shaped rib portions integral with said core portion and integrally interconnecting adjacent webs, the cross section of said insulator normal to the longitudinal axis thereof as defined by said webs being cruciform in configuration, one of said webs positioned on one side of said axis having an aperture extending transversely therethrough to accommodate a bolt for mounting hardware of a given potential and another of said webs positioned on an opposite side of said axis having an aperture extending transversely therethrough to accommodate a bolt for mounting hardware of a potential different than the potential of the hardware to be mounted on said one web, said apertures longitudinally spaced from each other and at least one of said rib portions positioned therebetween.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,516,585 Austin Nov. 25, 1924 1,715,889 Austin June 4, 1929 

